Airplane engine



March 1, 1932. Q GR|FF|TH 1,848,008

IRPLANE ENGINE Filed-Sept. 28, 1929 4 Sheets-Sheet l AIRPLANE ENGINEFiled Sept. 28. 1929 4 Sheets-Sheet f 2 A TTORNEYJ March 1, 1932. M, o.GRIFFITH AIRPLANE ENGINE 4 Sheets-Sheet 5 Filed Sep.. 28, 1929INI/'ENTOP ATTORNEY` March 1, 1932. M. o. GRIFFITH AIRPLANE ENGINE 4sheets-shea 4 Filed Sept. 28, 1929 IN VEN TOR.

Mall/aff,

A TTORNEYS.

Patented Mar. 1', 19,32

FUN-SHED( immer-MENA .MAX o. en irrignmor ciNcIVNNAm-Lbmo, VAssieriionTo PoWnrQcRosLEY, Jn., er"

CINcnintrn'rr,omoy` f l Ainrnmn ENGINE Y Y Application filed YVSeptember28,1929. `SerialiN'o. 395,940.

My invention'relates to enginesparticularly adapted for airplane useWhichjarelair cooled, and consequentlylare' made ofopen construction soas topermit of s uflcient radiiY ation. *Morefparticularly myinventionvre-y lates to in-line engines'as distinguished from rotary or radialengines. j

One object of my inventiqnlisto:

for an air cooled in-lineengine a camshaft and valve operating mechanismwhich -is'a unit and-can be removed and installed Withp i `finssurrounding the `cylinder lWalls as Well out destroying the timing ofthevalves.'A Y

`Another object is the provision for supply;` ing lubrication to thiscam "'shaitand V.valve operating assembly, and incidentally providingfor the" removal of eXCessoillfrom this portion of the engine.` Inconnection with?` this assembly, I furthermore arrange foraminimum 4ofinterference VWith full radiation of heat from the yheads'v of theengine Vcylin ders; Also I provide for aspheric'al-combus. tion chamberin the several cylinder'sand arrange the valve-operating mechanism andvvalves so that they operate normal to the spherical chamber, asdo'tliesparlrplugs.`

rangement oi'partslof which a typical exam-l` specication, andi thenovelty vinherent yin which lWill be duly claimed. A

In thedravvings:V

Figure 1 is a longitudinalvertical sectionof the engine. Y

p Figure 1a is a continuation: ofthe lower right hand corner oiFig-ure1... f I

Figurefl-isa plan view oit-one of the'valver access covers. "J7

Figure 5 's an outer end of the cam shai't'housing--'i Figure 6 .is `asectionall detail vof* the cam shaft unit on a largerl scale than Figure1.-" Y

Figure- 7 isA a cross section 'throughione of the rocker arm'sectionsthereof. f

These objects and advantages and other improvements, which Will'bepointed out I ac-` complish by that Vcertainconstruction andar-j ple isshown and. descri-bedrin theensuing a plee YeWOfy the iffsheft" nuelevational@ e the Figure 8 'is l an fend elevation? oit the "cam" shafthousing taken from. the opposite end 'of the same. from Figure 5, andomitting the rockerY armV portion soas? to show just the end oisaid`housing and containedparts. f

q Figure' 9 -is anl end elevation ofthe cam shaft-taken. at its innerend;

as th'ecombustion chambers. Asillustrated,

: `Figure 10 isan' elevationof thisfportion f the combustioncha'mbers 2`are formed Withfy V'a spherical surf-ace andthe ports 3 and-4 ffo'r'fthe inlet and 'exhaust valve are normal to this surface.v "SuitableWebs are cast in* the Ihea'dso' the cylinders as at'aA and 1a forguiding the valve stems, the said'vveb'sleav-V ing open spaces `5 at theside Jrior communi- 'cation With the inlet i and `outlet manifold,

andktheir lower partsbeingmachined toY .A

provide a base V6 to Which is mounted the housing for the camshaft androcker arms.'V The valves 7 and 8 have theirvstemsioV and Sa'ext'endingat a slantinto thespacesto be `occupied by the rohclker'arms.y Thecrank? shaft 9- is mounted on' spaced' bearings -10 which arellubricated from the pipe 11,as Will be noted. The gear case 12 ismounted' at the rear end of the engine in which 'case' are locateda.seriesof spur gea-rs generally.

marked 13 driven :fromthe Vcrank shaft and" lcoupled up sofas to driveaI stub shaft "14 yat thelower end of the gear casefvvhich shaft drivesthe lcam y f vvillkbe-noted'.'

F'gurej2 sja vertical crosssectionpof the shaft of the engine, asi

The various accessoriesloi theA engine are Y f driven from this gearcase'includmg the 'oilA pump; 15":"Wh1'ch pumps Q11` to Vthe variousparts of the engine,-a`nd in'additiongvvith-'" "rovi".- portionsfl? 1Theicanrshaft is formed off-a .hollow tube 18'. closedffat v'each fendby plugs' 19. -This sha-fthasportsQO/therein for distributing oil j toVjournal lblocks 21l` which are held in place in the narrow portions ofthe housing. The block 22 at the left hand end of the housing has an oilpassage 23 therein which is made to communicate with the oil deliverypipe 25. ln this way the bearing 22 differs from the bearings 2l andeach bearing, as will be apparent, will be held in place by a bolt 25 inthe several narrow portions of the housing. The housing terminates atone endin a cap 26,`and at the other end in a flange 27 which is boltedto the gear case surrounding the stub shaft 14. rlhe Wide portions ofthe housing are bolted to the base 6 byv means of bolts passing throughholes 27 in iianges 28 formed on each of the lateral projections of thewide portions of the housing. The cam shaft has formed thereon the cams29 which lie in the wide portions of the hou sing.' The inner end.

of the cam shaft isformedv with projecting lugsSO which are off centerof the cam shaft and register with matching notches 3l in the stub shaft14. The off-set relation ofV these lugs and notches is such that the camshaft can be connected to the stub shaft in yonly one position, therebymaking possible its removal and vreplacemelflt without changing.

the timing of the cams located on the shaft.

Opposite each valve stem as it lies-within the housing, is an opening32,.'.wh1ch'o'penf` ings are closed by means vof plates 34 adapted to bescrewed in place (Figures 4and 5).

" inside of the wide portions of the housing are webs 17a. These webshave portions 17?) therein which communicate with the wide portions ofthe housing.` The result of this constructionl is that the oil whichcollects in the rocker arm chamber or wide portions of the housingisfree to flow lengthwiseof the housing to what in the drawings istheright hand thereof where there is a port 41. This port communicateswith a passageway which forms a part of the housing and eXtendsthelength of the housing providing a return oil passage 42 thatcommunicates with the oil return pipe 43. rifhe return oil lpipe 44which eXtends from the aprons at the upper end of the cylinder also iscoupled with the passage-42, y

The. construction` of .cam shaftghousing in which there are divergingbranches to acu commodate valve stems which themselves diverge permitsmeto employ valves the ports it is desired to gain access to Vany rockerarm the cover 34 can be removed which is adjacent to that rocker armgiving full access to the arm, and any rocker arm can be removed andreplaced without disturbing the others and without dismounting thehousing by removing the` nuts 88 and driving out the mounting pin forthat'rocker arm.

Finally the entirehousing can be unbolted from the' base 6 and at 27whereupon it can be" removed from theengine,.and replacedwithouta'ffecting the timing of the valves in any way. It should benotedin this connection that the oil Vpipes will also have to bedisconnected if thehousing is to be removedu o It will be evident thatthe cam shaft and rocher arm arrangement' is very convenient and,that-repairs .can be made readily without takingthe engine to pieces sofar asV these parts` are concerned. Y

lt isquite important in aviation practice that repairs vcanbe made'tothe valve operating system.V without throwing the valves out ofy timeforthe reason that the timing must be accurately and carefullyl done,and often it is necessaryv to make repairsunder circumstances where thisis not practical.v It is also of great advantage, in case of thebreak-down of an engine, to be' able to replace a cam shaft and rockerarm equipment without dismantling the engine.

While I'have described my invention as applied to. cylinders inone lineonly, it is apparent that the device would be equally as practical in aV type arrangement in which the cylinders are in line but arranged atdiverging angles.

Having thus described my. invention, what I claim as new and desire tosecure by Letters Eatent, is y 1. In an airplane engine having cylindersin line, a unit assemblyformed o f a housing, and a-.cam shaft androckerarms mounted tliereimsaid assembly being removable andreplaceable on theengine, cam shaft operating means driven bytheengine, and interengagingmeans between the same,and the cam shaft permitting removal of theshaftendwise therefrom. c

2. In: an airplane engine aseries of cylinders arranged in line andinverted, a housing for the cam shaft of said engine located on theunder side* of saidcylinders, and a pas sagewayforming part 'of saidhousing and lut) providing a return conduit for oil'to the oil 1 pump ofthe engine.V l v l Y 3. A cam shaft and rocker arm housing for in lineairplane engines, comprising a housing member having wide portions andnarrow intermediate Y portions, bearings located in the narrow portionsof the housing for a Acam shaft,'and supports in the wide portions ofthehousingfor the vrocker arms.'

y 19 4.V A cam shaft and rocker arm housing for .Y Y

in line airplane engines, comprising a housing memberhaving wideportions and narrow intermediate portions, bearings located in thenarrow portions of thehousing for a l5 cam shaft, and supports in thewide portions of the housing for the rocker arms, said supportscomprising pins held in place by nuts on the `outside of the wideportions of the housing.

29 5. A cam shaft and rocker arm'housing for in line airplane engines,comp-risinga housving member having wide portions and narrowintermediate portions, bearings located in the narrow portions of thehousing fora cam shaft, and supports in the wide portions of the housingfor the rocker arms, and pas-` sages in the narrow portions of thehousing.,- communicating with the bottoms of the wide s portions of thehousing,.thus providing a.

' 30 continuous oil passage through' the bottom of the housing. f 6. Acam shaft and. rocker arm housing for in line airplane engines,comprising a hous- ,i ing member having wide portions and narp .lrow'interm-ediate portions, bearingsglocated in the narrow portionsofthe housing fora cam shaftand supports in the wideportions of thehousing for the rocker arms,.and pasj sages in the narrow portions ofthe housing 40 communicating with the bottoms of the wide portions ofthe housing, thus providing a continuous oil passage through the bottomof the housing, anda lower passage formed throughout the length ofthe/housing and communicating with the interior of the said housing.

MAX O. GRIFFITH.

